/... the hardest part is honestly removing the front grills to put the scoops in there.../
Partially agree - to all the other search result tips found from others who claim kidney grill replacement is a breeze and can be done without undoing the top of the bumper or being able to reach through the kidney grills, or even just 'pressing on the tabs', yada yada yada... bulllllllllllshit.
/...The duct just pulls straight up and out, it pops out of its grove and out.. .../
Hard to do the 1st time, may require twisting motion to loosen the vertical air duct. 2 vice grip pliers attached to the vertical air duct will be your best friends in this scenario.
/...Then put the duct back into place but pushing down and twisting left and right, you can use a long screwdriver also to try and get the bottom of the duct to pop back into place..
Where the duct goes down into its place, the plastic wheel liner is right next to it, you can push the wheel liner in towards the wheel so you make room for your hand to reach down and guide the duct in, this is what worked for me..
THIS was the hardest part of the install - I'm willing to bet there are others who did this install who thought they did this part right or worse, gave up and said fock it and just left the air duct disconnected.
Thank you for documenting this crucial tip - hoping that others searching this forum for help on re-installing the vertical air ducts with lower scoops back into place will find your tip via 'search' more easily.
(Caveat: unsure if this tip is only applicable to LCI models) Since the front bumper's lower air dam/duct (that the vertical air ducts connect to) are made of flexible plastic, twisting/pushing the vertical air ducts w/lower scoops installed back into place was not easy at all. Imagine pushing the vertical air duct into the top hole of an an empty tissue box that has 1 vertical side on the box removed. Very mushy and unstable.
My contributing tip... you may benefit from following 5soko's tip and then "guide" really means, use your hand to stabilize/pull up the outer lip of the flexible plastic base vertically against the direction of the vertical air duct until it pops back in place. Note: This still takes considerable effort but is much more feasible than without this tip.